How to Care for Cosmos Flowers

Long-lasting cosmos flowers attract birds, butterflies and bees.

Cosmos (C. bipinnatus) is a tall, trouble-free annual with colorful blooms that appear from mid-summer to the first frost. The soft pastel shades of the flowers attract butterflies, bees and birds, and the long-stemmed blooms are ideal for cut flower arrangements. Cosmos is a sturdy, drought-tolerant plant that does well even in poor soil types and blazing, hot sun.

Things You'll Need

• Wooden stakes
• Soft tie or fabric strips

Instructions

1. Plant cosmos in full sunlight or partial shade. Although cosmos will grow in poor soil, it's important that the soil drains well.

2. Water cosmos deeply when it begins to look wilted. Avoid watering the plants until the soil dries out again.

3. Stake tall cosmos varieties to keep the flowers standing upright. Drive a wooden stake into the ground a few inches from the plant, and tie the stems loosely to the stake with a soft tie or a strip of soft fabric.

4. Deadhead, or pinch off, spent blooms to encourage cosmos to continue blooming profusely as long as possible. Cosmos reseeds easily, so deadheading will keep the plant from growing out of control. If you want the plant to reseed itself, leave a few blooms on the stems in late summer.

Tips & Warnings

• Cut cosmos will last seven to 10 days in a vase filled with tepid water. Cut the blooms in the morning so the stems will be well-hydrated, and strip off the lower leaves so they won't be submerged in the vase.

• Cosmos are easy to dry. Just gather eight to 10 stems into a bunch and bind the ends together loosely with a string or rubber band. Hang the bunch upside down in a dry, warm, well-ventilated room for approximately two weeks.

References

• Cornell University: Cosmos (C. bipinnatus)
• Cosmos Produces Cosmic Beauty
• Old Farmer's Almanac: Cosmos